232 PHYSIOLOGY OF CENTRAL NERVOUS SYSTEM. 



lenticularis is connected with the posterior Rolandic region of the 

 cortex, the n. caudatus seems to be independent in this regard, 

 and to be provided with its own system of projection fibers. 

 With regard to the various nuclei of the thalamus, it is known that 

 they form abundant connections with the sensory areas of the cor- 

 tex cerebri, and from this standpoint they may be regarded as 

 consisting of subcenters, with a probability, however, that reflexes 

 may occur through them (subcortical reflexes) independently of 

 the cortex. Numerous fibers have been traced from the thalamus 

 to the body sense area (Flechsig) . Sachs* states that the thalamus 

 may be considered as being composed of two practically inde- 

 pendent parts : an inner division, which has relation with the nucleus 

 caudatus and the rhinencephalon, and an outer division, which, 

 on the one hand, serves as a terminus for the fibers of the lem- 

 riscus and of the superior cerebellar peduncle, and, on the other 

 hand, is connected by afferent and efferent paths with the cortex 

 of the Rolandic region. It is evident, from these relations and from 

 the proximity of the internal capsule, that lesions in the thalamus 

 may occasion symptoms of a very diverse character. Among 

 these symptoms, we should expect to find hemianesthesia on the 

 opposite side, owing to the fact that the thalamus serves as a sub- 

 station for the fibers of the lemniscus. 



* Sachs, "Brain," 1, 1909. 



